British number one Katie Boulter was defeated in the second round of the US Open, securing only one game in a 58-minute match against Karolina Muchova. The Czech seventh seed delivered a swift 6-1 6-0 victory.
Boulter's serve struggled, with eight double faults and no aces, and she won just 33% of points on her first serve. She was unable to save any of the seven break points she faced, accumulating 22 unforced errors compared to four winners.
The match, initially scheduled for an outer court, was moved to the 14,000-capacity Louis Armstrong Stadium due to heavy rain in New York.
In other British action, Francesca Jones had better fortune, returning to win her first-round match against Poland's Magda Linette after a rain interruption on Tuesday. Jones will now face either American 14th seed Iva Jovic or Poland's Magdalena Frech in the second round on Thursday. Jan Choinski, however, failed to progress, losing to Botic van de Zandschulp.